Germanium phthalocyanine films

Abstract

A process for preparing film structures comprising phthalocyanine oligomers having metal coordinating atoms in adjacent rings connected along a central axis through oxygen atoms. The ligands on the outermost rings of the structures are hydrophilic. The preferred coordinating atom is germanium and the structures may be prepared on a Langmuir-Blodgett balance using phthalocyanine oligomers in which one of the outermost rings is connected to a hydrophobic ligand while the other outermost ring is connected to a hydrophilic ligand. The pH of the subphase in the trough of the balance is maintained at a pH of from about 2 to 6, and the hydrophobic ligand is converted to a hydrophilic ligand during the process of coating a substrate by passing it upward through the film on the subphase.

What is claimed is: 
     
       1. A process for preparing a substrate coated with a film comprising: preparing a solvent solution of an amphiphilic, multiring compound containing at least two adjacent, parallel phthalocyanine rings having identical coordinating atoms selected from the group consisting of germanium and tin located at the center of the rings, said rings being interconnected along an axis perpendicular to their surfaces and passing through the centers thereof, by means of single oxygen atoms located along said axis, said oxygen atoms connecting the coordinating atoms in adjacent rings and in which the outermost ring at one end of said axis has a hydrophilic ligand selected from the group consisting of chloroacetoxy, dichloroacetoxy, trichloroacetoxy, fluoroacetoxy, difluoroacetoxy, trifluoroacetoxy, bromoacetoxy, dibromoacetoxy, tribromoacetoxy, iodoacetoxy, diodoacetoxy, and triodoacetoxy, attached to the coordinating atom thereof, while the outermost ring at the other end of said axis has a hydrophobic ligand attached to the coordinating atom thereof;   depositing said solution on an aqueous subphase, said subphase having a pH of from about 2 to 6, thereby hydrolyzing said hydrophilic ligands to hydroxyl ligands;   evaporating said solvent from said solution to provide a monolayer of said compound on said subphase;   compressing said monolayer to form a substantially continuous film, and   passing a substrate having a hydrophilic surface substantially vertically through said film, thereby hydrolyzing said hydrophobic ligand to a hydroxyl ligand and producing said coated substrate.   
     
     
       2. A process according to claim 1, in which said coordinating atoms are germanium. 
     
     
       3. A process according to claim 2, in which said hydrophobic ligand is a member selected from the group consisting of --OSiR 3  where R has at least about 6 carbon atoms and may be the same or different and may contain oxygen, nitrogen or sulfur atoms; OC 6  X 4  R', where X iS H or an alkyl group with up to 5 carbon atoms and may contain oxygen, sulfur or nitrogen atoms, and R' has at least about 10 carbon atoms and may contain oxygen, nitrogen or sulfur atoms; and OR", where R", has at least about 10 carbon atoms and may contain oxygen, nitrogen or sulfur atoms. 
     
     
       4. A process according to claim 3, in which said hydrophilic ligand is hydroxo. 
     
     
       5. A process according to claim 4, in which said hydrophobic ligand is --OSiR 3  and said hydrophilic ligand is a member selected from dichloroacetoxy, trichloroacetoxy, dibromoacetoxy, tribromoacetoxy and fluoroacetoxy. 
     
     
       6. A process according to claim 1, in which said compound contains two said adjacent parallel phthalocyanine rings. 
     
     
       7. A process according to claim 1, in which said solvent is dichloromethane. 
     
     
       8. A coated substrate comprising a) a substrate and,   b) a film of a multi-ring compound deposited on the substrate, the film havng at least two layers, each layer of said film comprising at least two adjacent, parallel phthalocyanine rings having identical coordinating atoms selected from the group consisting of germanium and tin located at the center of the rings, said rings being interconnected along an axis perpendicular to their surface and passing through the center thereof by means of an oxygen atom connecting the coordinating atoms in adjacent rings, and in which the outermost rings at both ends of said axis of each of said layers have a hydroxo ligand attached to the coordinating atoms thereof.   
     
     
       9. A process for preparing a substrate coated with a Langmuir-Blodgett film comprising: preparing a solvent solution of an amphiphilic multiring compound containing two adjacent, parallel phthalocyanine rings having germanium coordinating atoms, said rings being interconnected along an axis perpendicular to their ring surfaces and passing through the centers thereof by means of single oxygen atoms located along said axis, said oxygen atoms connecting the coordinating atoms in adjacent rings and in which the outermost ring at a first end of said axis has a ligand member selected from the group consisting of --OSiR 3  where R has at least about 6 carbon atoms and may be the same or different and may contain oxygen, nitrogen or sulfur atoms; OC 6  X 4  R', where X is H or an alkyl group with up to 5 carbon atoms and may contain oxygen, sulfur or nitrogen atoms, and R' has at least about 10 carbon atoms and may contain oxygen, nitrogen or sulfur atoms; and OR", where R" has at least about 10 carbon atoms and may contain oxygen, nitrogen or sulfur atoms, and wherein the outermost ring at a second end of said axis is a hydrophilic halogen acetoxy ligand selected from the group consisting of chloroacetoxy, dichloroacetoxy, trichloroacetoxy, fluoroacetoxy, difluoroacetoxy, trifluoroacetoxy, bromoacetoxy, dibromoacetoxy, tribromoacetoxy, iodoacetoxy, diodoacetoxy, and triodoacetoxy,   depositing said solution on an aqueous subphase contained in a Langmuir-Blodgett balance, said subphase having a pH of from about 3 to 4;   evaporating said solvent from said solution to provide an expanded monolayer of said compound on said subphase;   compressing said expanded monolayer to form a substantially continuous film, and   passing a substrate having a hydrophilic surface upwardly through said film, thereby producing said coated substrate.